Doped Silicon Oxide Deposition by Atmospheric Pressure and Low Temperature Chemical Vapor Deposition Using Tetraethoxysilane and Ozone

Doped silicon oxides, phosphosilicate glass (PSG), and borosilicate glass (BSG) films were deposited using organic doping sources, trimethylphosphate for PSG films, and trimethylborate (TMB) and SlOB for BSG films. Deposition rate, doping level, film stress, etching rate by an aqueous HF solution, IR spectra and leakage current of the films were studied. In PSG deposition, a P205 content up to 6 mole percent (m/o), a deposition rate of as high as 150 nm/min and a film stress of less than 1 x 109 dyne/cm 2 were obtained at 400 ~ IR spectra showed that the PSG films were very stable even after boiling in water. Step coverage on aluminum steps was conformal or slightly nonconformal, and base material dependence of deposition rate was not observed, which would indicate a partial gas-phase reaction even in TEOS/O3 atmospheric pres-sure chemica l vapor deposit ion. The extent of the nonconformal i ty was much smal ler than that of the si lane-base PSG films. In BSG deposi t ion a 200 nm/min deposit ion rate, a 1 • 109 dyne/era 2 film stress and a 14 m/o dop ing level were ob-tained at 400 ~ The stress of films depos i ted at 400 ~ relaxed f rom tensile to compress ive, 0.2 • 109 dyne/era 2. Leakage current of TMB/BSG films was very low, 15 nA/cm 2, w i thout anneal ing independent of dop ing level. S tep coverage of both films was very conformal, however, base material dependence of deposit ion rate was observed. Both phenomena are the same as the USG case, but different f rom the PSG deposition. IR spectra of both films proved that the films were accepta-bly stable several days after deposition